We propose studies related to the pathogenesis of the rise in ocular pressure in primary open angle glaucoma. Two approaches are a study of steroid induced glaucoma and the measurement of aqueous flow rate by fluorophotometry. Steroid glaucoma may be related to primary open angle glaucoma and may be the first "Biochemical Handle" to this disease. We wish to determine whether or not this is the case. In addition our aim is to elucidate the mechanism of the steroid induced pressure rise. The methods include the determination of plasma cortisol before and after oral dexamethasone in normal and glaucomatous patients, the induction and study of steroid glaucoma in animals, in vitro uptake studies of various substances in animal and human irises (the latter obtained at cataract surgery) and the in vitro effect of steroids on mucopolysaccharide sulfation in iris tissue. The current clinical method of measuring aqueous flow rate by tonography or suction cup contain multiple sources of error. The most promising clinical method is that of Maurice with an objective fluorophotometer and iontophore of fluorescein across the cornea. This instrument has been constructed in our laboratory. Normal patients and glaucoma patients in various stages will be studied. The undersigned agrees to accept responsibility for the scientific and technical conduct of the project and for provision of required progress reports if a grant is awarded as the result of this application.